Pub Date : 2026-05-01Epub Date: 2026-01-23DOI: 10.1016/j.euromechsol.2026.106040
Ziyi Liu, Haikuan Dong, Guanhua Zheng, Qiang Gao
In this paper, an efficient finite element method (FEM) is developed for vibroacoustic analysis of sandwich and honeycomb panels in an infinite fluid domain. The infinite fluid domain is approximated by a sufficiently large cubic domain, whose size is determined according to the sound radiation and wave decay criteria. Within the frequency range of interest (100–5000 Hz), the mesh resolution adaptively refined according to wavelength and the frequency-dependent finite element model is established to balance accuracy and computational efficiency. Moreover, an iterative algorithm separates the fluid-structure interaction equation into structural and fluid equations. Then, the structural equation is solved directly, while the fluid equation is efficiently handled using the Kronecker product, which transforms the large n3-order matrices into a series of n-order operations and significantly reduces computational cost. Numerical examples demonstrate that the proposed method accurately predicts the vibroacoustic response of sandwich and honeycomb panels. Compared with Ansys simulation, the proposed method maintains high accuracy, with CPU time reduced by 8–24 times.
{"title":"Vibroacoustic analysis of sandwich and honeycomb panels using an efficient FEM approach","authors":"Ziyi Liu, Haikuan Dong, Guanhua Zheng, Qiang Gao","doi":"10.1016/j.euromechsol.2026.106040","DOIUrl":"10.1016/j.euromechsol.2026.106040","url":null,"abstract":"<div><div>In this paper, an efficient finite element method (FEM) is developed for vibroacoustic analysis of sandwich and honeycomb panels in an infinite fluid domain. The infinite fluid domain is approximated by a sufficiently large cubic domain, whose size is determined according to the sound radiation and wave decay criteria. Within the frequency range of interest (100–5000 Hz), the mesh resolution adaptively refined according to wavelength and the frequency-dependent finite element model is established to balance accuracy and computational efficiency. Moreover, an iterative algorithm separates the fluid-structure interaction equation into structural and fluid equations. Then, the structural equation is solved directly, while the fluid equation is efficiently handled using the Kronecker product, which transforms the large <em>n</em><sup>3</sup>-order matrices into a series of <em>n</em>-order operations and significantly reduces computational cost. Numerical examples demonstrate that the proposed method accurately predicts the vibroacoustic response of sandwich and honeycomb panels. Compared with Ansys simulation, the proposed method maintains high accuracy, with CPU time reduced by 8–24 times.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"117 ","pages":"Article 106040"},"PeriodicalIF":4.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2025-11-27DOI: 10.1016/j.euromechsol.2025.105962
S. Shahab Ghafouri , M. Soltani , M.H. Momenian , O. Civalek
In this research, the free vibration behavior along with the stability analysis of two parallel three-layer sandwich beams made of porous materials and integrated with metallic face sheets inter-connected by a set of translational springs are assessed. The contemplated structure is placed on Winkler’s elastic foundation and subjected to an axial mechanical load. By considering the effects of shear deformation within the framework of Timoshenko beam model, and using the method of calculus of variations and Hamilton’s principle, the system of governing motion equations of the corresponding structure is obtained and analytically solved via Navier’s method and Fourier series functions for simply supported boundary conditions. The dispersion of internal pores is considered based on three different patterns through the thickness of the beam and its effect on the natural frequencies and endurable buckling loads of the under-investigation model is precisely investigated. Also, the impact of the changes in the porosity coefficient, aspect ratio, thickness ratio, and stiffness of elastic medium is comprehensively explored. Furthermore, the effect of tensile and/or compressive axial preloading on the natural frequencies of the contemplated double-bonded system is perused in detail. The obtained results indicate that changes in theses parameters have a remarkable influence on the stability and vibration performance of the system, and by considering appropriate design quantities, it is possible to attain the desired buckling capacity and vibrational characteristics, while minimizing the weight of the structure.
{"title":"Impact of axial preloading on the vibrational response of a double FG porous sandwich beam system surrounded by elastic medium","authors":"S. Shahab Ghafouri , M. Soltani , M.H. Momenian , O. Civalek","doi":"10.1016/j.euromechsol.2025.105962","DOIUrl":"10.1016/j.euromechsol.2025.105962","url":null,"abstract":"<div><div>In this research, the free vibration behavior along with the stability analysis of two parallel three-layer sandwich beams made of porous materials and integrated with metallic face sheets inter-connected by a set of translational springs are assessed. The contemplated structure is placed on Winkler’s elastic foundation and subjected to an axial mechanical load. By considering the effects of shear deformation within the framework of Timoshenko beam model, and using the method of calculus of variations and Hamilton’s principle, the system of governing motion equations of the corresponding structure is obtained and analytically solved via Navier’s method and Fourier series functions for simply supported boundary conditions. The dispersion of internal pores is considered based on three different patterns through the thickness of the beam and its effect on the natural frequencies and endurable buckling loads of the under-investigation model is precisely investigated. Also, the impact of the changes in the porosity coefficient, aspect ratio, thickness ratio, and stiffness of elastic medium is comprehensively explored. Furthermore, the effect of tensile and/or compressive axial preloading on the natural frequencies of the contemplated double-bonded system is perused in detail. The obtained results indicate that changes in theses parameters have a remarkable influence on the stability and vibration performance of the system, and by considering appropriate design quantities, it is possible to attain the desired buckling capacity and vibrational characteristics, while minimizing the weight of the structure.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"117 ","pages":"Article 105962"},"PeriodicalIF":4.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-08DOI: 10.1016/j.euromechsol.2026.106018
Monzer Daoud , Régis Kubler
Shot-peening is a surface treatment process widely employed to enhance the fatigue life of metallic components by inducing compressive residual stresses beneath the surface. However, such components often contain surface or subsurface geometrical defects that can reduce fatigue life. Accurate understanding of the resulting residual mechanical fields near these defects is essential for integrating shot-peening into the design process and accurately predicting the fatigue life. This study investigates the evolution of residual mechanical fields both near and far from an artificial hole (800 μm in diameter and 400 μm in depth), as well as the associated edge-hole distortion after shot-peening. A finite element framework was employed to compare two approaches: a multi-impact shot-peening model and an eigenstrain reconstruction method incorporating elastoplastic behavior. Both approaches were applied to TRIP780 steel, using experimental material parameters as inputs and experimental residual stress profiles for validation. Results showed that the multi-impact shot-peening model successfully simulated the localized plastic deformation adjacent to the hole, where strain concentration and distortion extended up to 200 μm from the edge. Although the eigenstrain method could not reproduce the edge-hole distortion, it generated comparatively similar localized plastic deformation near the hole and provided accurate residual stress predictions at distances beyond 200 μm from the hole, owing to inputs from the multi-impact shot-peening model. Both approaches indicated that the radial stresses were more influenced by the hole than the tangential ones.
{"title":"Shot-peening simulations with artificial surface defect using multiple impacts and eigenstrain reconstruction method","authors":"Monzer Daoud , Régis Kubler","doi":"10.1016/j.euromechsol.2026.106018","DOIUrl":"10.1016/j.euromechsol.2026.106018","url":null,"abstract":"<div><div>Shot-peening is a surface treatment process widely employed to enhance the fatigue life of metallic components by inducing compressive residual stresses beneath the surface. However, such components often contain surface or subsurface geometrical defects that can reduce fatigue life. Accurate understanding of the resulting residual mechanical fields near these defects is essential for integrating shot-peening into the design process and accurately predicting the fatigue life. This study investigates the evolution of residual mechanical fields both near and far from an artificial hole (800 μm in diameter and 400 μm in depth), as well as the associated edge-hole distortion after shot-peening. A finite element framework was employed to compare two approaches: a multi-impact shot-peening model and an eigenstrain reconstruction method incorporating elastoplastic behavior. Both approaches were applied to TRIP780 steel, using experimental material parameters as inputs and experimental residual stress profiles for validation. Results showed that the multi-impact shot-peening model successfully simulated the localized plastic deformation adjacent to the hole, where strain concentration and distortion extended up to 200 μm from the edge. Although the eigenstrain method could not reproduce the edge-hole distortion, it generated comparatively similar localized plastic deformation near the hole and provided accurate residual stress predictions at distances beyond 200 μm from the hole, owing to inputs from the multi-impact shot-peening model. Both approaches indicated that the radial stresses were more influenced by the hole than the tangential ones.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"117 ","pages":"Article 106018"},"PeriodicalIF":4.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-31DOI: 10.1016/j.euromechsol.2026.106050
Lan Chen , Lei Zhu , Yibo Huang , Xinzhou Zhang , Lijia Fang , Haisheng Zhao , Shu Huang , Xudong Ren
Triply periodic minimal surface (TPMS) structures possess unique advantages including interconnected porosity, high specific surface area, and tunable mechanical properties, enabling their widespread applications in biomedical engineering and energy storage devices. Despite the revolutionary fabrication capabilities offered by additive manufacturing for porous lattice structures, the influence of process-induced interlayer bonding on structural performance remains unclear. To address this issue, this study innovatively integrates the mechanical characteristics of P-type and IWP-type unit cells to construct novel hybrid lattice structures via Boolean operations and smoothing functions, fabricated using selective laser melting (SLM) with Ti-6.5Al-2Zr-Mo-V powder. This research highlights the generation of these new hybrid structures and systematically reveals the effect of SLM build orientation on the compressive mechanical performance of porous architectures. Results show that all structures exhibit superior load-bearing performance when loaded parallel to the build direction, with the P + IWP hybrid structure achieving the highest platform stress (352.72 MPa) and specific energy absorption (SEA) (8.85 J/g), significantly outperforming the individual P-type and IWP-type structures. Notably, the P-IWP hybrid structure maintains comparable mechanical performance to the P-type structure despite a 25% reduction in relative density, while exhibiting enhanced mechanical isotropy, indicating that the subtractive fusion strategy achieves both lightweight characteristics and structural stability. Overall, the proposed hybrid design strategy offers an effective approach to enhance the energy absorption capacity, mechanical isotropy, and engineering applicability of TPMS porous structures, demonstrating broad potential for biomedical implants, impact protection, and energy absorption devices.
{"title":"Directional compressive behavior of SLM-fabricated fused porous structures under two distinct loading directions","authors":"Lan Chen , Lei Zhu , Yibo Huang , Xinzhou Zhang , Lijia Fang , Haisheng Zhao , Shu Huang , Xudong Ren","doi":"10.1016/j.euromechsol.2026.106050","DOIUrl":"10.1016/j.euromechsol.2026.106050","url":null,"abstract":"<div><div>Triply periodic minimal surface (TPMS) structures possess unique advantages including interconnected porosity, high specific surface area, and tunable mechanical properties, enabling their widespread applications in biomedical engineering and energy storage devices. Despite the revolutionary fabrication capabilities offered by additive manufacturing for porous lattice structures, the influence of process-induced interlayer bonding on structural performance remains unclear. To address this issue, this study innovatively integrates the mechanical characteristics of P-type and IWP-type unit cells to construct novel hybrid lattice structures via Boolean operations and smoothing functions, fabricated using selective laser melting (SLM) with Ti-6.5Al-2Zr-Mo-V powder. This research highlights the generation of these new hybrid structures and systematically reveals the effect of SLM build orientation on the compressive mechanical performance of porous architectures. Results show that all structures exhibit superior load-bearing performance when loaded parallel to the build direction, with the P + IWP hybrid structure achieving the highest platform stress (352.72 MPa) and specific energy absorption (SEA) (8.85 J/g), significantly outperforming the individual P-type and IWP-type structures. Notably, the P-IWP hybrid structure maintains comparable mechanical performance to the P-type structure despite a 25% reduction in relative density, while exhibiting enhanced mechanical isotropy, indicating that the subtractive fusion strategy achieves both lightweight characteristics and structural stability. Overall, the proposed hybrid design strategy offers an effective approach to enhance the energy absorption capacity, mechanical isotropy, and engineering applicability of TPMS porous structures, demonstrating broad potential for biomedical implants, impact protection, and energy absorption devices.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"117 ","pages":"Article 106050"},"PeriodicalIF":4.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2025-12-01DOI: 10.1016/j.euromechsol.2025.105976
Zhenyuan Zhang, Yujie Zhao, Honglin Li, Zhonghao Tang, Lei Li
This study presents a structural additive optimization method designed to reduce vibrations in complex dynamic systems. Conventional optimization techniques, such as topology, shape, and sizing optimization, often encounter difficulties in addressing dynamic loading and manufacturing constraints. To address these challenges, the proposed method introduces targeted material addition at structural points with maximum dynamic displacement, thereby increasing stiffness and mitigating vibrations. The method's effectiveness is demonstrated through its application to a helicopter rotor system, which is characterized by intricate dynamic responses and operational complexities. Finite element modeling, transient dynamic analysis, and iterative optimization are employed to validate the approach. The results show a maximum displacement reduction of 41.01 %, indicating substantial improvements in structural stiffness and vibration suppression, while achieving this outcome with markedly lower computational cost compared to conventional size optimization methods. This research underscores the feasibility and adaptability of structural additive optimization under varying operational loads, offering a robust alternative to traditional methods. The findings have practical implications for vibration-sensitive engineering systems in which dynamic performance and structural integrity are paramount.
{"title":"A structural additive optimization method and its application in vibration reduction of helicopter rotor systems","authors":"Zhenyuan Zhang, Yujie Zhao, Honglin Li, Zhonghao Tang, Lei Li","doi":"10.1016/j.euromechsol.2025.105976","DOIUrl":"10.1016/j.euromechsol.2025.105976","url":null,"abstract":"<div><div>This study presents a structural additive optimization method designed to reduce vibrations in complex dynamic systems. Conventional optimization techniques, such as topology, shape, and sizing optimization, often encounter difficulties in addressing dynamic loading and manufacturing constraints. To address these challenges, the proposed method introduces targeted material addition at structural points with maximum dynamic displacement, thereby increasing stiffness and mitigating vibrations. The method's effectiveness is demonstrated through its application to a helicopter rotor system, which is characterized by intricate dynamic responses and operational complexities. Finite element modeling, transient dynamic analysis, and iterative optimization are employed to validate the approach. The results show a maximum displacement reduction of 41.01 %, indicating substantial improvements in structural stiffness and vibration suppression, while achieving this outcome with markedly lower computational cost compared to conventional size optimization methods. This research underscores the feasibility and adaptability of structural additive optimization under varying operational loads, offering a robust alternative to traditional methods. The findings have practical implications for vibration-sensitive engineering systems in which dynamic performance and structural integrity are paramount.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"117 ","pages":"Article 105976"},"PeriodicalIF":4.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2025-12-02DOI: 10.1016/j.euromechsol.2025.105983
Hamed Momeni-Khabisi , Masoud Tahani
This study presents a comprehensive thermo-mechanical stability analysis of an imperfect rectangular piezo-flexomagnetic nano-plate. The theoretical model simultaneously incorporates both piezomagnetic and direct flexomagnetic effects, enabling a more comprehensive representation of magneto-mechanical coupling phenomena at the nanoscale. To capture the size-dependent behavior inherent to such nano-structures, the strain-gradient theory is employed through the inclusion of a material length-scale parameter. The governing differential equations and corresponding boundary conditions are derived based on the von Kármán nonlinear strain–displacement relations, classical plate theory, and principle of minimum total potential energy. Closed-form analytical solutions are obtained for critical buckling and post-buckling behavior under mechanical, thermal, and coupled thermo-mechanical loading conditions for both roller and hinge edge supports. The analytical formulation is validated through comparisons with benchmark results reported in the literature. A parametric investigation is conducted to evaluate the effects of key parameters—including flexomagnetic coupling, aspect ratio, boundary conditions, initial geometric imperfection, and thermal loading—on the buckling and post-buckling response of the nano-plate. The numerical results reveal that the influence of the flexomagnetic effect is more pronounced under uniaxial in-plane loading compared to biaxial loading. Additionally, in biaxial loading conditions, the impact of the flexomagnetic property is significantly greater for aspect ratios less than unity. The stability performance of the nano-plate shows consistent improvement due to flexomagnetic effects for both uniaxial and biaxial loading scenarios. Size effects play a critical role in nanoscale structural behavior, as evidenced by the substantial increase in critical buckling load with the length-scale parameter. Geometric imperfections generally lower the critical load, though their impact on the post-buckling response varies with both imperfection magnitude and boundary constraints. Thermal loading demonstrates a more pronounced destabilizing effect compared to purely mechanical loading, particularly in plates with imperfections. Boundary conditions substantially influence the structural response: roller supports offer greater initial load capacity, whereas hinged supports develop enhanced membrane stiffening at larger deformation amplitudes. These findings offer valuable insights for the design and development of smart two-dimensional nano-devices where flexomagnetic coupling can be utilized for enhanced stability control.
{"title":"Size-dependent thermo-mechanical stability of flexomagnetic nano-plates with initial imperfections","authors":"Hamed Momeni-Khabisi , Masoud Tahani","doi":"10.1016/j.euromechsol.2025.105983","DOIUrl":"10.1016/j.euromechsol.2025.105983","url":null,"abstract":"<div><div>This study presents a comprehensive thermo-mechanical stability analysis of an imperfect rectangular piezo-flexomagnetic nano-plate. The theoretical model simultaneously incorporates both piezomagnetic and direct flexomagnetic effects, enabling a more comprehensive representation of magneto-mechanical coupling phenomena at the nanoscale. To capture the size-dependent behavior inherent to such nano-structures, the strain-gradient theory is employed through the inclusion of a material length-scale parameter. The governing differential equations and corresponding boundary conditions are derived based on the von Kármán nonlinear strain–displacement relations, classical plate theory, and principle of minimum total potential energy. Closed-form analytical solutions are obtained for critical buckling and post-buckling behavior under mechanical, thermal, and coupled thermo-mechanical loading conditions for both roller and hinge edge supports. The analytical formulation is validated through comparisons with benchmark results reported in the literature. A parametric investigation is conducted to evaluate the effects of key parameters—including flexomagnetic coupling, aspect ratio, boundary conditions, initial geometric imperfection, and thermal loading—on the buckling and post-buckling response of the nano-plate. The numerical results reveal that the influence of the flexomagnetic effect is more pronounced under uniaxial in-plane loading compared to biaxial loading. Additionally, in biaxial loading conditions, the impact of the flexomagnetic property is significantly greater for aspect ratios less than unity. The stability performance of the nano-plate shows consistent improvement due to flexomagnetic effects for both uniaxial and biaxial loading scenarios. Size effects play a critical role in nanoscale structural behavior, as evidenced by the substantial increase in critical buckling load with the length-scale parameter. Geometric imperfections generally lower the critical load, though their impact on the post-buckling response varies with both imperfection magnitude and boundary constraints. Thermal loading demonstrates a more pronounced destabilizing effect compared to purely mechanical loading, particularly in plates with imperfections. Boundary conditions substantially influence the structural response: roller supports offer greater initial load capacity, whereas hinged supports develop enhanced membrane stiffening at larger deformation amplitudes. These findings offer valuable insights for the design and development of smart two-dimensional nano-devices where flexomagnetic coupling can be utilized for enhanced stability control.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"117 ","pages":"Article 105983"},"PeriodicalIF":4.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-28DOI: 10.1016/j.euromechsol.2026.106043
Rui Barreira , Nils Koltzenburg , Robin Wieland , Selcuk Mentese , Uwe Kramer , Bekim Berisha
This work introduces a novel physics-based model to track and quantify damage-induced degradation in metallic conductors through the increase in electrical resistance. We hypothesize this degradation is driven by the growth of internal porosity, and propose an evolution law for the decrease in material conductivity based on the Voigt–Reuss composite bounds with a single fitting parameter. To relate the local conductivity with the effective resistance of a conductor, a novel homogenization scheme based on power equivalency principles is also introduced. Our model is validated on copper microvias under interconnect stress test conditions for which experimental data are collected. Finite element simulations of 200 complete thermal cycles are performed for both stacked and staggered microvia configurations, with geometries derived from scanning electron microscopy measurements. The proposed model fits the industrial experimental data well, improving upon existing models by over one order of magnitude. The analysis is extended with a crystal plasticity constitutive model informed by electron backscatter diffraction texture data, which revealed highly localized plastic strain hotspots within the grain structure, preferential sites for void nucleation and growth. This provides direct evidence for the mechanism that creates porosity within the microvia, validating the fundamental assumptions of our model.
{"title":"Void growth drives electrical resistance increase: A physics-based damage model for ductile metallic conductors","authors":"Rui Barreira , Nils Koltzenburg , Robin Wieland , Selcuk Mentese , Uwe Kramer , Bekim Berisha","doi":"10.1016/j.euromechsol.2026.106043","DOIUrl":"10.1016/j.euromechsol.2026.106043","url":null,"abstract":"<div><div>This work introduces a novel physics-based model to track and quantify damage-induced degradation in metallic conductors through the increase in electrical resistance. We hypothesize this degradation is driven by the growth of internal porosity, and propose an evolution law for the decrease in material conductivity based on the Voigt–Reuss composite bounds with a single fitting parameter. To relate the local conductivity with the effective resistance of a conductor, a novel homogenization scheme based on power equivalency principles is also introduced. Our model is validated on copper microvias under interconnect stress test conditions for which experimental data are collected. Finite element simulations of 200 complete thermal cycles are performed for both stacked and staggered microvia configurations, with geometries derived from scanning electron microscopy measurements. The proposed model fits the industrial experimental data well, improving upon existing models by over one order of magnitude. The analysis is extended with a crystal plasticity constitutive model informed by electron backscatter diffraction texture data, which revealed highly localized plastic strain hotspots within the grain structure, preferential sites for void nucleation and growth. This provides direct evidence for the mechanism that creates porosity within the microvia, validating the fundamental assumptions of our model.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"117 ","pages":"Article 106043"},"PeriodicalIF":4.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2025-12-29DOI: 10.1016/j.euromechsol.2025.106009
Jie Luo , Yiwen Li , Guangyan Liu , Kai Zhang
Accurate identification of structural parameters from deformation fields remains a pivotal objective in theoretical research and engineering practice. As inverse-problem methodologies evolve, engineering applications now require parameter identification at unprecedented spatial scales and levels of fidelity. Conventional approaches, however, encounter substantial limitations when applied to large-scale structures, primarily because of the high dimensionality, nonlinearity, and heterogeneity inherent in full-field deformation data. Inspired by multi-scale decomposition principles, this study introduces a segmentation–assembly–optimization (SAO) framework that systematically reduces the complexity of large-scale inverse problems. A lightweight convolutional neural network (CNN) is trained to map local displacement fields onto their corresponding structural parameters; these local estimates are subsequently assembled and refined by a mechanics-driven optimization procedure to reconstruct the global parameter distribution. Comprehensive numerical experiments demonstrate that the proposed framework achieves accuracies exceeding 98 % within the region of interest (ROI) for large-scale structures with intricate geometries, and maintains robust reconstruction accuracy (>90 % under 1 % noise), whereas the standalone CNN performance degrades significantly. The SAO framework thereby overcomes scale-dependent constraints and delivers a reliable, data-driven solution for high-resolution structural identification.
{"title":"Study on data-driven inverse identification of structural parameters for large-scale structures","authors":"Jie Luo , Yiwen Li , Guangyan Liu , Kai Zhang","doi":"10.1016/j.euromechsol.2025.106009","DOIUrl":"10.1016/j.euromechsol.2025.106009","url":null,"abstract":"<div><div>Accurate identification of structural parameters from deformation fields remains a pivotal objective in theoretical research and engineering practice. As inverse-problem methodologies evolve, engineering applications now require parameter identification at unprecedented spatial scales and levels of fidelity. Conventional approaches, however, encounter substantial limitations when applied to large-scale structures, primarily because of the high dimensionality, nonlinearity, and heterogeneity inherent in full-field deformation data. Inspired by multi-scale decomposition principles, this study introduces a segmentation–assembly–optimization (SAO) framework that systematically reduces the complexity of large-scale inverse problems. A lightweight convolutional neural network (CNN) is trained to map local displacement fields onto their corresponding structural parameters; these local estimates are subsequently assembled and refined by a mechanics-driven optimization procedure to reconstruct the global parameter distribution. Comprehensive numerical experiments demonstrate that the proposed framework achieves accuracies exceeding 98 % within the region of interest (ROI) for large-scale structures with intricate geometries, and maintains robust reconstruction accuracy (>90 % under 1 % noise), whereas the standalone CNN performance degrades significantly. The SAO framework thereby overcomes scale-dependent constraints and delivers a reliable, data-driven solution for high-resolution structural identification.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"117 ","pages":"Article 106009"},"PeriodicalIF":4.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-02DOI: 10.1016/j.euromechsol.2025.106014
Hui Zhang , Yu Zhang , Wei Sun , Haitao Luo , Hongwei Ma , Kunpeng Xu
To address the difficulties regarding mechanical property fluctuations and vibration control of carbon fiber reinforced composite (CFRC) structures in environments with coupled high temperatures and time-varying loads, this study centers on identifying the temperature dependence of the elastic and damping parameters of CFRC and devising vibration control approaches. Firstly, experimental tests are conducted to acquire the natural frequencies and modal damping ratios of CFRC plates at various temperatures. Then, a dynamic model of the CFRC plate that takes temperature dependence into account is built, and via inverse identification, the nonlinear patterns of how the elastic modulus and loss factor change with temperature are uncovered. Subsequently, by introducing the concept of fractional-order differentiation, a novel fractional-order linear extended state observer-sliding mode control (FOLESO-SMC) strategy is proposed. This method enhances the dynamic capturing capability of the system, enabling precise estimation of the states of the system under time-varying load disturbances and rapid response to compensate for the vibrations of the system. Finally, the generality of the temperature dependence parameters of CFRC is fully validated. Through both simulation calculations and experimental tests, it is verified that FOLESO-SMC can effectively cope with the dual influences of the thermal environment and complex time-varying loads, thus achieving efficient vibration suppression. This study addresses the research gap concerning the active vibration control applied to CFRC structures under the coupled effect of thermal environments and time-varying loads, laying a foundation for the intelligent vibration control of such structures in extreme service scenarios by providing theoretical support and technical safeguards.
{"title":"Temperature-dependent identification and active vibration control under time-varying loads for composite laminates","authors":"Hui Zhang , Yu Zhang , Wei Sun , Haitao Luo , Hongwei Ma , Kunpeng Xu","doi":"10.1016/j.euromechsol.2025.106014","DOIUrl":"10.1016/j.euromechsol.2025.106014","url":null,"abstract":"<div><div>To address the difficulties regarding mechanical property fluctuations and vibration control of carbon fiber reinforced composite (CFRC) structures in environments with coupled high temperatures and time-varying loads, this study centers on identifying the temperature dependence of the elastic and damping parameters of CFRC and devising vibration control approaches. Firstly, experimental tests are conducted to acquire the natural frequencies and modal damping ratios of CFRC plates at various temperatures. Then, a dynamic model of the CFRC plate that takes temperature dependence into account is built, and via inverse identification, the nonlinear patterns of how the elastic modulus and loss factor change with temperature are uncovered. Subsequently, by introducing the concept of fractional-order differentiation, a novel fractional-order linear extended state observer-sliding mode control (FOLESO-SMC) strategy is proposed. This method enhances the dynamic capturing capability of the system, enabling precise estimation of the states of the system under time-varying load disturbances and rapid response to compensate for the vibrations of the system. Finally, the generality of the temperature dependence parameters of CFRC is fully validated. Through both simulation calculations and experimental tests, it is verified that FOLESO-SMC can effectively cope with the dual influences of the thermal environment and complex time-varying loads, thus achieving efficient vibration suppression. This study addresses the research gap concerning the active vibration control applied to CFRC structures under the coupled effect of thermal environments and time-varying loads, laying a foundation for the intelligent vibration control of such structures in extreme service scenarios by providing theoretical support and technical safeguards.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"117 ","pages":"Article 106014"},"PeriodicalIF":4.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-20DOI: 10.1016/j.euromechsol.2026.106031
Y.X. Zhao , Y. Cai , R.C. Pan , N.B. Zhang , Tao Liu , K. Li , L. Lu , S.N. Luo
Plate impact experiments are conducted on pure polyimide, a 15% graphite filled polyimide composite, and a 15% graphite/10% polytetrafluoroethylene (PTFE) filled polyimide composite, to investigate their compression and spall damage under ultrahigh strain rate loading. The Hugoniot equation of state (shock adiabat) of polyimide is measured up to a peak shock stress of 1.6 GPa with the reverse-impact method. Free-surface velocity histories of polyimide/polyimide composites are measured to deduce their dynamic mechanical properties, including spall strength, interfacial strength, and tensile strain rate. The addition of graphite leads to sequential interfacial debonding and matrix fracture. The graphite/matrix interface tensile strength is approximately 0.05 GPa for the two composites. Spall strength shows negligible dependence on impact velocity for the three materials studied. X-ray computed tomography is conducted on both pre- and post-impact samples. Compared to pure polyimide, the fracture surfaces of the graphite-filled polyimide composite exhibit increased roughness; the debonding at the graphite-polyimide interfaces provides numerous void nucleation sites, results in a more discrete damage distribution, but delays the fracture of the matrix. The incorporation of PTFE reduces matrix integrity, leading to more significant spall damage and a reduction in spall strength. Our present findings not only enhance the understanding of damage mechanisms in graphite-filled polyimide composites, but also provide valuable guidance for the application of polymer composites in protective and structural materials.
{"title":"Ultrahigh strain rate compression and tensile fracture in polyimide and polyimide-based composites: A comparative study","authors":"Y.X. Zhao , Y. Cai , R.C. Pan , N.B. Zhang , Tao Liu , K. Li , L. Lu , S.N. Luo","doi":"10.1016/j.euromechsol.2026.106031","DOIUrl":"10.1016/j.euromechsol.2026.106031","url":null,"abstract":"<div><div>Plate impact experiments are conducted on pure polyimide, a 15% graphite filled polyimide composite, and a 15% graphite/10% polytetrafluoroethylene (PTFE) filled polyimide composite, to investigate their compression and spall damage under ultrahigh strain rate loading. The Hugoniot equation of state (shock adiabat) of polyimide is measured up to a peak shock stress of 1.6 GPa with the reverse-impact method. Free-surface velocity histories of polyimide/polyimide composites are measured to deduce their dynamic mechanical properties, including spall strength, interfacial strength, and tensile strain rate. The addition of graphite leads to sequential interfacial debonding and matrix fracture. The graphite/matrix interface tensile strength is approximately 0.05 GPa for the two composites. Spall strength shows negligible dependence on impact velocity for the three materials studied. X-ray computed tomography is conducted on both pre- and post-impact samples. Compared to pure polyimide, the fracture surfaces of the graphite-filled polyimide composite exhibit increased roughness; the debonding at the graphite-polyimide interfaces provides numerous void nucleation sites, results in a more discrete damage distribution, but delays the fracture of the matrix. The incorporation of PTFE reduces matrix integrity, leading to more significant spall damage and a reduction in spall strength. Our present findings not only enhance the understanding of damage mechanisms in graphite-filled polyimide composites, but also provide valuable guidance for the application of polymer composites in protective and structural materials.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"117 ","pages":"Article 106031"},"PeriodicalIF":4.2,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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